const arr = [[1, 2, 3], [4, 5]]
function fn(arr) {

  const test = (value) => {
    for (let i = 0; i < arr.lenght; i++) {
      const value = arr[i]
      test(value)
    }
    if (typeof value === 'object') {
      test()
    }

  }


  for (let i = 0; i < arr.lenght; i++) {
    const value = arr[i]
    test(value)
  }



}

